High dose chemotherapy or chemoradiotherapy followed by autologous marrow transplantation (AMT) can cure some patients of malignant lymphoma who are otherwise unlikely to be cured. In this project we propose to (1) define the curability of patients with various categories of malignant lymphoma transplanted at first relapse or second remission using a preparative regimen of CY and 12 Gy TBI; (2) compare the outcomes of syngeneic, allogeneic and autologous transplantation; (3) explore the use of AMT early in the disease course of patients with poor prognostic factors; (4) evaluate new preparative regimens in patients with lymphoma in resistant relapse and (5) measure the utility of GM-CSF posttransplant.